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Aperture to see DSOs as more than smudges

Posted: Wed Jun 16, 2021 10:48 pm
by Vern
As my subject says, what aperture telescope would I need to see DSOs as more than smudges? I have a meade star navigator NG 125mak and the diameter is 127mm. I bought it last year and can see star clusters and the Andromeda galaxy. I have not been able to see other galaxies. At what aperture would I start to see individual stars in star clusters and would the cluster be brighter? What aperture is needed to see galaxies, say the sombrero or pinwheel galaxy?

Would a larger and more expensive telescope have a more accurate goto? I use a two star alignment on my star navigator and then click on the guided tour/tonights best. I have had go right to a target and can see it in the eye piece, other times (sometimes the same session) it will be close but I can't see the target and need to slew the telescope to find it. When I try to see the sombrero galaxy I don't know if the telescope isn't pointed at it or my telescope isn't big enough.

I am near Fenton Michigan and lightpollutionmap.info shows my location as Bortle 5.

Re: Aperture to see DSOs as more than smudges

Posted: Wed Jun 16, 2021 11:44 pm
by notFritzArgelander
In my experience DSOs like galaxies and globular star clusters start pleasing me starting at 8" aperture. However my Intes MK66 is no slouch at 6". With Bortle 5 you should be in decent shape. OTOH I had some nice views of M51 with my 4" f11 TS ED scope and beautiful views of nebular details with the SV ED 80.

It may depend upon your expectations to some extent? The brighter DSOs can be viewed with a small scope. To resolve a globular or see details in galaxies the bigger the better and as I said, 8" is where things start to get really good. I can do the whole Messier catalog with my VMC110L which is smaller aperture than your Mak by a little. The fainter items are smudgy though.

You might want to check on your goto procedure. If the NG allows you to add more stars to get a better alignment, try that. I find that 2 stars are often iffy and often add 1 or 2 additional or calibration stars when I want to be secure.

Get a piece of planetarium SW like Cartes du Ciel or Stellarium. Then you can get an idea of the magnification needed to distinguish the target. You should be able to find the Sombrero with your present rig, for sure.

Re: Aperture to see DSOs as more than smudges

Posted: Thu Jun 17, 2021 12:36 am
by Ylem
8 seems to really open things up.
I have a 127, 6 and an 8, the 6 is brighter, but the 8 resolves.

Re: Aperture to see DSOs as more than smudges

Posted: Thu Jun 17, 2021 1:08 am
by sdbodin
I have seen spiral arms of M51 in my old 6" newt, but only in the deep high desert with mag 7.5 skies, almost as dark as space itself. From the rural location I live in now, my 16 just faintly shows M51 arms and the brighter galaxies extend faintly to their full size. BUT, they never look like a Hubble photo, that's why I have switched to taking pictures.

Tired of faint fuzzies,
Steve

Re: Aperture to see DSOs as more than smudges

Posted: Thu Jun 17, 2021 1:38 am
by gregl
As to goto and slewing, while I don't know about the Meade, with any spur-gear driven scope there will be backlash in the gears. In my Celestron 8SE, there is a routine to correct for that, although even that doesn't produce perfect results. The problems usually arise when I align and observe for a while east of the meridian but then when I slew around to the west things start to get off. It's because the gears are pushing the scope up when east and pushing it down when west. I have thought about putting a sandbag on the outboard end of the OTA to keep it down so the slack in the gears is always the same but haven't gotten around to trying it. (This is for the alt.; for the az., be sure to always approach from the same direction.)

So you might to check to see if there is some sort of correction routine for your scope.

Re: Aperture to see DSOs as more than smudges

Posted: Thu Jun 17, 2021 3:34 am
by Refractordude
I would look for campsites in the light green area I have circled. Looks like you are one hour drive to Sleepy Hollow State Park. There is a campsite that I once used. They would charge me $15 for the night. I would set up before sunset and stargaze for about 5 hours and leave. It is a one and a half hour drive from me. I have a new spot that is free next to a small apartment building in a Bortle 4 zone. Left click the image.

Re: Aperture to see DSOs as more than smudges

Posted: Thu Jun 17, 2021 3:37 am
by Lady Fraktor
Though aperture will definitely help what eyepieces are you using to view with?

Re: Aperture to see DSOs as more than smudges

Posted: Thu Jun 17, 2021 4:18 am
by Refractordude
Once while observing M104/Sombrero galaxy I put a patch over my eye and waited 15 minutes. I put a black towel over my head for a second observation and could see the bulge of the galaxy. It was not bright as in some photos, but the patch trick help show more than a faint black line/dust lane with a white spot in the middle.

Re: Aperture to see DSOs as more than smudges

Posted: Thu Jun 17, 2021 10:46 am
by Vern
I have 9.7mm, 15mm, 20mm and 26mm eyepieces, most of the time I use the 26mm. These are meade super plossl eyepieces.

My telescope might find five targets in a row then be a little off on the next, then be right on the one after that. I think some of it is software and some from the gears in the mount. I will have to look in the menu to train the drive again. I did update the software in the audiostar controller last winter. Are the gears in the mount serviceable?

I looked at the audiostar menu structure I printed out and it has easy, one star & two star alignments.

From the replies it looks like I should start looking at 8" telescopes when I want a new one.

Re: Aperture to see DSOs as more than smudges

Posted: Thu Jun 17, 2021 12:06 pm
by KingNothing13
Refractordude wrote: Thu Jun 17, 2021 4:18 am I put a black towel over my head for a second observation and could see the bulge of the galaxy. It was not bright as in some photos, but the patch trick help show more than a faint black line/dust lane with a white spot in the middle.
I am so uncoordinated I have yet to master the art of the eyepatch and the towel (or shirt) over the head thing. Somethng always seems to go wrong! I really need to put together a good system!

Re: Aperture to see DSOs as more than smudges

Posted: Thu Jun 17, 2021 1:52 pm
by GCoyote
Vern wrote: Thu Jun 17, 2021 10:46 am I have 9.7mm, 15mm, 20mm and 26mm eyepieces, most of the time I use the 26mm. These are meade super plossl eyepieces.

My telescope might find five targets in a row then be a little off on the next, then be right on the one after that. I think some of it is software and some from the gears in the mount. I will have to look in the menu to train the drive again. I did update the software in the audiostar controller last winter. Are the gears in the mount serviceable?

I looked at the audiostar menu structure I printed out and it has easy, one star & two star alignments.

From the replies it looks like I should start looking at 8" telescopes when I want a new one.

You have a newer version of the model I'm working on now. The gears are not hard to get to but unless you bought the scope used and need to check for wear or dirt, there is not much you can do inside. Polymer gears don't need lubricant and there are no adjustable parts that a user can easily fine tune.

The previous advice about alignment, sync, and backlash mirror what I've read on the Meade elsewhere. If you are new to astronomy, it may be that you need to get more experience before you consider getting "more scope."

This is the best place I've found yet for positive and practical advice.

Clear Skies!

Re: Aperture to see DSOs as more than smudges

Posted: Thu Jun 17, 2021 3:38 pm
by gregl
GCoyote wrote: Thu Jun 17, 2021 1:52 pm ....
If you are new to astronomy, it may be that you need to get more experience before you consider getting "more scope."
....

If you can, go to a star party sponsored by a local club. (Call someone first — sometimes members have limited observing time and may not be prepared to help you if you just show up.) Not only can they help you with the scope, they can help you learn what you can see with what you have. Different scopes have different capabilities and one is not better or worse than another. They just are better for certain things. Some folks I know have several scopes and choose the one they use based on what they want to see.

Having said that, the most common scope in my club seems to be the 8-inch SCT. It's not the best choice for some things but it may be the best compromise between size and aperture.

Re: Aperture to see DSOs as more than smudges

Posted: Thu Jun 17, 2021 4:35 pm
by turboscrew
T-shirt goes over the head. The towel goes on the shoulder. :joking:

Re: Aperture to see DSOs as more than smudges

Posted: Thu Jun 17, 2021 5:25 pm
by pakarinen
KingNothing13 wrote: Thu Jun 17, 2021 12:06 pm I am so uncoordinated I have yet to master the art of the eyepatch and the towel (or shirt) over the head thing. Somethng always seems to go wrong! I really need to put together a good system!
I bought an oversized black hoodie from 32 Degrees. It's some kind of light, stretchy fabric so it's comfortable even when it's warmer outside. I pull the hood over my head and EP like Emperor What's-his-name in "Star Wars". I like their t-shirts and lounge pants too and they're pretty inexpensive.

The upsidedown t-shirt over the head works also.

Re: Aperture to see DSOs as more than smudges

Posted: Thu Jun 17, 2021 6:18 pm
by KingNothing13
pakarinen wrote: Thu Jun 17, 2021 5:25 pm
KingNothing13 wrote: Thu Jun 17, 2021 12:06 pm I am so uncoordinated I have yet to master the art of the eyepatch and the towel (or shirt) over the head thing. Somethng always seems to go wrong! I really need to put together a good system!
I bought an oversized black hoodie from 32 Degrees. It's some kind of light, stretchy fabric so it's comfortable even when it's warmer outside. I pull the hood over my head and EP like Emperor What's-his-name in "Star Wars". I like their t-shirts and lounge pants too and they're pretty inexpensive.

The upsidedown t-shirt over the head works also.
Palpatine! :D

I have a ton of hoodies, but I don't know how they would work in the summer heat. :think:

Re: Aperture to see DSOs as more than smudges

Posted: Thu Jun 17, 2021 6:24 pm
by pakarinen
Check out the 32 Degree ones. Seriously, they are the coolest (temperature-wise) that I've seen. Good for keeping skeeters off too since they're lightweight. But, as always, YMMV.

Re: Aperture to see DSOs as more than smudges

Posted: Thu Jun 17, 2021 7:06 pm
by GCoyote
pakarinen wrote: Thu Jun 17, 2021 6:24 pm Check out the 32 Degree ones. Seriously, they are the coolest (temperature-wise) that I've seen. Good for keeping skeeters off too since they're lightweight. But, as always, YMMV.
If bugs are still a problem, you can spray a max strength bug repellant on the fabric so you don't have to have so much on your skin.

Re: Aperture to see DSOs as more than smudges

Posted: Fri Jun 18, 2021 12:33 am
by Vern
While I have only had my telescope for a year I understand enough about it that if I want to see objects in more detail and brighter I will need a bigger one. That is why I wanted to know what is the smallest bigger telescope that would work.

I will go through the 'train drive' in the setup menu again just in case. I also see that there is a calibrate motor and high precision selection, I will have to look into those.

I usually push enter to hear a description of what is next on the guided tour/tonights best, then goto. Most of the time when I just push goto it slews to the new object, but sometimes it will only move a little when it should go to the opposite side of the sky or it will move alot when it should move a little. It must be a software glitch and I can get it back on track by pushing mode to go back and start over.

If other meade telescopes use the same level of software as I have regardless of the size of the telescope then I assume they could also have this glitch.

Are the motors & gears in the mounts for larger telescopes made of better quality materials or to closer tolerances so they are more accurate?

Re: Aperture to see DSOs as more than smudges

Posted: Fri Jun 18, 2021 1:20 am
by gregl
While I'm not familiar with the Meade offerings, the Celestron Evolution series has brass worm gears which should have less backlash than spur gears. It's still a single-arm mount so you might want to investigate the fork mount scopes. My 8SE single arm is quite wiggly when focusing or even in a strong breeze.

Don't buy sight unseen. By the time you put some of these scopes into a case of some sort you can end up with a rather large package.

Re: Aperture to see DSOs as more than smudges

Posted: Fri Jun 18, 2021 2:09 am
by sdbodin
Vern wrote: Fri Jun 18, 2021 12:33 am

If other meade telescopes use the same level of software as I have regardless of the size of the telescope then I assume they could also have this glitch.

Are the motors & gears in the mounts for larger telescopes made of better quality materials or to closer tolerances so they are more accurate?
I have the biggest Meade and the goto accuracy is first rate. Always on target in my camera fov the first time. However, planets are a different story and it has to do with the ephemeris loaded into the scope's computer, not enough bits to be accurate after a few years, so the finder is needed.

Steve